The Evaluation of Chlorpyrifos Ethyl Degradation in Tea-Planting Soil in Bao Loc, Lam Dong using Biomix Biodegradation Model Supplemented with Penicillium chrysogenum N2

Abstract

This study investigates the capability of treating chlorpyrifos ethyl (CE) – a common pesticide – using a biomix composting model in tea-growing soil in Bảo Lộc, Lâm Đồng, Vietnam. Lâm Đồng, with the largest tea cultivation area in the country, spanning 23,000 hectares and producing 71,000 tons of tea annually, faces significant soil pollution due to excessive pesticide use, particularly CE. Chlorpyrifos ethyl is a potent neurotoxin with high persistence in soil and slow degradation. The biomix compost, consisting of tea soil, straw, peat, and lignin-degrading fungi, was prepared with initial parameters: 60% moisture, pH 6.95, 21.03% organic carbon, 1.29% total nitrogen, and a carbon-to-nitrogen ratio (C/N) of 16.30. Penicillium chrysogenum N₂, a lignin-degrading fungus with 173.2 U/kg activity, was added to the biomix at a 5% ratio to enhance CE degradation. Results showed that CE degradation efficiency ranged from 96% to 99% after 30 days, with CE concentrations from 10ppm to 150ppm, under optimal conditions of 60% moisture, 37°C temperature, and pH 6. The study also monitored the changes in the physicochemical properties of the biomix, indicating that temperature, moisture, and pH variations were conducive to microbial growth and CE degradation. These findings underscore the practical potential of microbial composting in treating pesticide pollution, contributing to environmental protection and sustainable agricultural development.